Patch "usb: quirks: add control message delay for 1b1c:1b20" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

    usb: quirks: add control message delay for 1b1c:1b20

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-quirks-add-control-message-delay-for-1b1c-1b20.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.

From cb88a0588717ba6c756cb5972d75766b273a6817 Mon Sep 17 00:00:00 2001

From: Danilo Krummrich <redacted>
Date: Tue, 6 Mar 2018 09:38:49 +0100
Subject: usb: quirks: add control message delay for 1b1c:1b20

From: Danilo Krummrich <redacted>

commit cb88a0588717ba6c756cb5972d75766b273a6817 upstream.

Corsair Strafe RGB keyboard does not respond to usb control messages
sometimes and hence generates timeouts.

Commit de3af5bf259d ("usb: quirks: add delay init quirk for Corsair
Strafe RGB keyboard") tried to fix those timeouts by adding
USB_QUIRK_DELAY_INIT.

Unfortunately, even with this quirk timeouts of usb_control_msg()
can still be seen, but with a lower frequency (approx. 1 out of 15):

[   29.103520] usb 1-8: string descriptor 0 read error: -110
[   34.363097] usb 1-8: can't set config #1, error -110

Adding further delays to different locations where usb control
messages are issued just moves the timeouts to other locations,
e.g.:

[   35.400533] usbhid 1-8:1.0: can't add hid device: -110
[   35.401014] usbhid: probe of 1-8:1.0 failed with error -110

The only way to reliably avoid those issues is having a pause after
each usb control message. In approx. 200 boot cycles no more timeouts
were seen.

Addionaly, keep USB_QUIRK_DELAY_INIT as it turned out to be necessary
to have the delay in hub_port_connect() after hub_port_init().

The overall boot time seems not to be influenced by these additional
delays, even on fast machines and lightweight distributions.

Fixes: de3af5bf259d ("usb: quirks: add delay init quirk for Corsair Strafe RGB keyboard")
Cc: stable@vger.kernel.org
Signed-off-by: Danilo Krummrich <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/core/message.c |    4 ++++
 drivers/usb/core/quirks.c  |    3 ++-
 include/linux/usb/quirks.h |    3 +++
 3 files changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c

@@ -147,6 +147,10 @@ int usb_control_msg(struct usb_device *d
 
 	ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
 
+	/* Linger a bit, prior to the next control message. */
+	if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
+		msleep(200);
+
 	kfree(dr);
 
 	return ret;
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c

@@ -229,7 +229,8 @@ static const struct usb_device_id usb_qu
 	{ USB_DEVICE(0x1b1c, 0x1b13), .driver_info = USB_QUIRK_DELAY_INIT },
 
 	/* Corsair Strafe RGB */
-	{ USB_DEVICE(0x1b1c, 0x1b20), .driver_info = USB_QUIRK_DELAY_INIT },
+	{ USB_DEVICE(0x1b1c, 0x1b20), .driver_info = USB_QUIRK_DELAY_INIT |
+	  USB_QUIRK_DELAY_CTRL_MSG },
 
 	/* Corsair K70 LUX */
 	{ USB_DEVICE(0x1b1c, 0x1b36), .driver_info = USB_QUIRK_DELAY_INIT },
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h

@@ -56,4 +56,7 @@
  */
 #define USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL	BIT(11)
 
+/* Device needs a pause after every control message. */
+#define USB_QUIRK_DELAY_CTRL_MSG		BIT(13)
+
 #endif /* __LINUX_USB_QUIRKS_H */

Patches currently in stable-queue which might be from danilokrummrich@dk-develop.de are

queue-4.4/usb-quirks-add-control-message-delay-for-1b1c-1b20.patch